[papajam]

The owners manual says either Shell Dentax 90 or AGIP F.1 Rotra SAE 90. This is for the stock gearbox with non-moly syncros. If the box has been converted to moly syncros or a later box (1968 and on), then Alfa recommends either Shell Spirax 90 EP, AGIP F.1 Rotra Hypoid SAE 90 or ESSO Gear Oil GX 90.